Just lifted this from the ATSB report on the A380 uncontained engine failure.
The GREEN hydraulic system is one of two primary hydraulic systems on the A380. Hydraulic power is supplied by engine-driven pumps on Nos 1 and 2 engines.
The YELLOW hydraulic system is the second of two primary hydraulic systems on the A380. Hydraulic power is supplied by engine-driven pumps on Nos 3 and 4 engines.
As a Concorde ancient, to me the primary hydraulic (and flight control) systems are called BLUE and GREEN, and YELLOW is the 'fall-back'.
When did this 'convention' change ?
"Confused"